<template>
  <!-- 
* 需求1: 铺设页面, 准备初始的数据(自己手写数据结构) - 前面是数组索引+1 *作为序号 √
* 需求2: 当输入框没有值, 要给用户一个提示, 必须都有值才能增加新数据 (数据驱动页面哦)  
* 需求3: 添加功能 - 想好数据结构统一对象的key  √
* 需求4: 点击编辑功能, 把值赋予到输入框上(不要操作dom, 数据驱动页面)
* 需求5: 用户修改后, 点击相同按钮 - 想想怎么判断怎么是添加还是修改的功能 (提示: 准备一个全局变量, 点过编辑按钮可以让它为true) - 实现编辑后更新页面效果
* 需求6: 点击删除, 删除这行数据  √
 -->
  <div>
    <div>
      <span>姓名:</span>
      <input type="text" v-model.trim="username" />
    </div>
    <div>
      <span>年龄:</span>
      <input type="number" v-model.number="userage" />
    </div>
    <div>
      <span>性别:</span>
      <select v-model="gender">
        <option value="男">男</option>
        <option value="女">女</option>
      </select>
    </div>
    <div>
      <button @click="addUpdate()">添加/修改</button>
    </div>
    <div>
      <table
        border="1"
        cellpadding="10"
        cellspacing="0"
        v-show="arr.length > 0"
      >
        <tr>
          <th>序号</th>
          <th>姓名</th>
          <th>年龄</th>
          <th>性别</th>
          <th>操作</th>
        </tr>
        <tr v-for="(item, index) in arr" :key="index">
          <td>{{ index + 1 }}</td>
          <td>{{ item.name }}</td>
          <td>{{ item.age }}</td>
          <td>{{ item.sex }}</td>
          <td>
            <button @click="del(index)">删除</button>
            <button @click="edit(index)">编辑</button>
          </td>
        </tr>
      </table>
    </div>
  </div>
</template>
<script>
export default {
  data() {
    return {
      arr: [
        { name: "Tom", age: 19, sex: "男" },
        { name: "Jone", age: 21, sex: "女" },
      ],
      username: "",
      userage: "",
      gender: "男",
      editcount: "",
    };
  },
  methods: {
    addUpdate() {
      let obj = {
        name: this.username,
        age: this.userage,
        sex: this.gender,
      };
      if (this.editcount !== null) {
        this.$set(this.arr, this.editcount, obj);
        this.editcount = null;
      } else {
        this.arr.push(obj);
      }
    },
    del(index) {
      this.arr.splice(index, 1);
    },
    edit(index) {
      let objEdit = this.arr[index];
      this.username = objEdit.username;
      this.userage = objEdit.userage;
      this.gender = objEdit.sex;

      this.editcount = index;
    },
  },
};
</script>
